Active energy ray-curable composition and optical recording medium having cured product of the composition

Abstract

An active energy ray-curable composition comprising (A) an epoxy resin, (B) a compound selected from the group consisting of sulfonium salts and cyclopentadienyl iron compounds, (C) a compound selected from the group consisting of acrylates, methacrylates and oligomers thereof, and (D) an organic peroxide, and optionally (E) a rubber component. The composition is useful for an adhesive layer of an optical recording medium.

We claim: 
     
       1. An optical recording medium comprising (I) optical disc substrates made of an ethylene/cycloolefin copolymer consisting substantially of (1) units represented by the following formula (1) ##STR17##  wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , and R 12 , independently from each other, represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 20 carbon atoms, R 9  may be bonded to R 11  or R 12  to form a 3- to 6-membered ring, R 10  may be bonded to R 11  or R 12  to form a 3- to 6-membered ring, n is a positive integer, and when n is at least 2, two or more R 5 , R 6 , R 7  or R 8  groups each may be identical or different and   (2) units represented by the formula   --CH.sub.2 CH.sub.2 --                                     (2)     and       (II) an adhesive layer of a composition comprising as a primary ingredient (A) an epoxy resin, (B) a compound selected from the group consisting of sulfonium salts and cyclopentadienyl iron compounds, (C) a compound selected from the group consisting of acrylates, methacrylates and oligomers thereof, and (D) an organic peroxide.   
     
     
       2. The optical recording medium of claim 1 in which the adhesive layer is the surface of the optical disc substrate and is deposited in the area having a particular radius from its center. 
     
     
       3. The optical recording medium of claim 1 in which the epoxy resin (A) is derived from a glycidyl ether of bisphenol A. 
     
     
       4. The optical recording medium of claim 1 in which the cycopentadienyl iron compounds (B) are cyclopentadienyl isopropylphenyl iron salts. 
     
     
       5. The optical recording medium of claim 1 in which the compound (C) is an ester of acrylic or methacrylic acid with an alcohol having a cyclohydrocarbon group, or an oligomer of the ester. 
     
     
       6. The optical recording medium of claim 1 in which the compound (C) is a mono- or poly-acrylate or a polymethacrylate of a polyester polyol, or an oligomer of the acrylate or methacrylate.